Is It Safe To Take Prednisone For Eosinophilic Faciatis?

For two years I have suffered from eosinophilic faciatis (sp?) The doctor has me take prednisone (as much as 20 mg) for two weeks and then taper off. This helps symptoms go away but then once I'm off, the count shoots back up and my symptoms, lethargy, soreness in limbs and puffiness, return. I am 44 years old. I have had a bone marrow test, MRI, and Pet scan. All came back with no cancer. I have had some tooth problems. Could I have an infection in my jaw bone that would cause this? Also, I was tested for parasites back when this first started and that too was negative. I'm currently tapered down to 7mg of prednisone and I feel my symptoms returning. Anything you can offer would be appreciated.